DNA makes RNA makes protein makes fungal cells

Abstract

The Mycota (Vol. VIII) – Biology of the Fungal Celledited by R.J. Howard and N.A.R. GowSpringer Verlag, 2001.£110.00 (hbk) (xvi + 307 pages)ISBN 3 450 60186 4In the preface to this volume, the editors Richard Howard and Neil Gow state that they hope to bridge the gaps between mycologists in different disciplines involved in fungal cell biology. These gaps are perhaps at their widest in methodology. The molecular genetic approach to understanding structure and function is used to some degree by almost all mycologists. However, fungi, particularly perhaps, present issues of interaction and complexity that require approaches based on physiology, classical morphology at both light and electron microscope level and biophysics. It is interesting how this volume emphasises this diversity of approach.To take two examples, the volume opens with a fascinating account of the biophysics of hyphal cell extension by Nicholas Money. (How many mycologists know that fungi can invade rock?) Questioning the current nucleic acid-based methodologies for the understanding of cell function, Money suggests that genetic analysis can only provide limited help and that mechanical approaches using fine-strain gauges and other instrumentation have provided, and will continue to provide, answers and insights. In contrast to this, the next chapter is a tour-de-force of the now classical reverse genetic approach to understanding yeast cell growth in Saccharomyces cerevisiae by Sheu and Snyder. Although there is still much to learn, a picture is emerging of the proteins that interact to initiate budding, site selection, directed cell wall synthesis and coordination with other cellular events. The text is heavy going, with a mutant acronym on at least every line in places. However, as a resource for yeast researchers from graduate student to professor (most undergraduates will almost certainly find the chapter too daunting!) it is bound to become essential reading.Other chapters continue to vary in the extent to which genetic analysis is discussed. Brown and Gow chart the progress of applying molecular genetics to Candida albicans whereas other chapters on ions as regulators, plant pathogens and colonial growth rely more on physiology, morphology and mathematical modelling.The second part of the volume is entitled ‘Structural continuum’ and the chapters start with a secreted protein family, the hydrophobins, and work inwards, with two chapters on the cell wall, followed by the cytoskeleton–plasma membrane–cell wall interactions. Once inside the cell, there are chapters on the microtubular cytoskeleton with its various motile activities and the motile tubular vacuole systems.This is a rich mixture of biological questions and technical approaches written by people who obviously know their fields well. The result is a very important collection of summaries, observations and theories that provides a valuable source of information for anyone working on fungi and particularly their cell biology. Inevitably, the focus is on recent findings, although the extent to which studies from more than ten years ago are cited varies considerably between chapters. Particularly timely are the two chapters on the cell wall by LaJean Chaffin and Nobel et al. at a time when a new antifungal agent targeting the cell wall has recently been launched.Perhaps the odd one out is the final chapter. In their introduction to the volume, Gow and Howard state ‘there are many topics that could not be addressed in such limited space, but no matter’. This is a little dismissive and I'm sure that they would agree that getting the right mix of chapters that reflects our understanding of the workings of all parts of the fungal cell does matter. Thus, my only reservation about this excellent volume is the final chapter, ‘Genomics for Fungi’ by Bennet and Arnold. The chapter itself is a fine and comprehensive treatment of approaches to genomic analysis generally and in fungi. However, it does not quite ‘fit’ into the continuum of cellular organization and interaction that the editors were aiming for. It is understandable that the editors wished to acknowledge the growing contribution of genomics to the understanding of fungal cell biology and how the expression of the genome creates the cell in all its complexity. However, I suspect that a future volume in the excellent Mycota series will need to be devoted to genomics itself and the final chapter might have been better there. Its exclusion could have been an opportunity for a chapter on more cell biological aspects of the nucleus including mitosis or DNA replication.I am sure that this volume of first-rate reviews will succeed, as the editors hope, in bridging the gaps between mycologists – in all their diversity – in the search for an understanding of the fungal cell – in all its complexity.